The present invention relates to a multicolor offset printing press that performs multicolor offset printing at once on a target printing product.
To print a bank note, securities, and the like, multicolor offset printing presses disclosed in Japanese Utility Model Registration No. 2524289 (literature 1) and Japanese Patent Laid-Open No. 2-22057 (literature 2) are used.
The multicolor offset printing press disclosed in literature 1 performs Simultan printing on the two surfaces of a sheet. This multicolor offset printing press includes a pair of blanket cylinders that perform printing on a sheet, four plate cylinders in contact with one blanket cylinder, and four plate cylinders in contact with the other blanket cylinder. The multicolor offset printing press performs four-color Simultan printing on the obverse surface of a sheet and also performs four-color Simultan printing on the reverse surface of the sheet.
The multicolor offset printing press disclosed in literature 2 includes a pair of blanket cylinders that perform printing on a sheet, four plate cylinders in contact with one blanket cylinder, two plate cylinders in contact with the other blanket cylinder, and a Sammeldruck collecting plate cylinder in contact with the other blanket cylinder. A Sammeldruck collecting blanket cylinder is in contact with the Sammeldruck collecting plate cylinder. Three Sammeldruck pattern plate cylinders are in contact with the Sammeldruck collecting blanket cylinder. This multicolor offset printing press is a double-sided multicolor offset Sammeldruck printing press.
Forgery prevention is always requested of a printing press that prints a bank note and securities. In order to prevent forgery, it is effective to increase the number of colors of printing products. Thus, the above-mentioned multicolor offset printing press needs to further increase the number of colors from the viewpoint of forgery prevention.